Saturday, December 10, 2011

Jewelry casting 1:1

I have a wild imagination when creating jewelry. I love curvy and romantic shapes and sometimes, sheet and wire just doesn't cut it as a medium. If I for instance want to create a little dragon, I need true 3D and the only way to get that is through casting.

You can cast in a number of ways, for instance sand casting, which I often use as a quick solution. However, noting beats ”cire perdue” or ”lost wax” casting when it comes to 3 dimensionality. And that requires really large and expensive equipment in your workshop or help from professional casters. Luckily I have the latter and so in august I threw myself into creating the ”Dragonling” plus a number of other elements I had wanted for a long time.

So, in order to end up with a lovely piece of jewelry, I started with wax. Very hard, non-yielding wax, which can be cut into very thin and delicate shapes. I had been working with it before, but on a much smaller scale. Now I got ambitious. I wanted a whole collection of leaves and flowers to play with, some settings for drops and of cause the little dragon I had been dreaming about for over one year.

When you work with wax you become a true sculptor. This is the same process Michelanngelo uses when he starts with a piece of marble, knowing that inside of it the perfect David is hiding.

So here is an example of my process: I wanted to create a pendant featuring large drops of stone or pearl and hence needed the settings for the drops. Therefore I started out by carving the seat for the stone intended to go there – in this case a drop-shaped and very lovely amethyst. I use my trusted Foredom flex shaft motor (yep, this is basically the drill they use at the dentist. The sound is also the same ;-)

Then I roughly cut the shape I wanted for the setting and sat back, turning it between my fingers. Was this right? Was this what I wanted? Maybe a tad deeper here and this one a bit to the left?

Slowly I worked through the various stages, constantly refining the shape...

Until I used a scraper (how very non-power-toolish in the old school and very nice way) to shape and smooth the surface until I was satisfied. This will do – for now.

Same drill with the Dragonling, the flowers and leaves. In the end I had a nice collection of stuff to be cast and hence collected the various elements on branches for the caster to work with. Here are some of them:

So, what happens at the caster? Well, he glues the branches onto a stem of wax together with other items to be cast, thereby creating a whole tree. The tree is fixed to a rubber base and after finishing, a iron tube is slipped over the whole thing, resting on the base. Then he fills the tube with plaster and puts it into a vacuum in order to remove any bubbles (which would create some very unfortunate shapes on the finished casts).

When the cast has cured and dried, it is put into an oven where it is heated up to a very high degree – melting the wax out of the tube. Now the wax is truly ”lost”. In the meantime, he starts up the centrifugal casting machine by melting the metal needed. In this case silver. At the right moment, when all has the right temperature, he inserts the very hot tube into the machine and starts it. Automatically it shoots the liquid metal into the tube, pushing it into all the nooks and crannies.

When I receive the casts they look dull and almost white. Nothing resembling the shiny silver to eventually come out of this.

Now, this is when I could just cut out the pieces and use them. They would be true one-of-a-kind items. However, I wanted more – I wanted to be able to use the same shape in a number of different ways and so I had to have replicas made. Oh dear... the process isn't over yet – at all!

Back at my bench, I shaped (some were a tad too thick) and renovated everything as well as possible. Renovating means smoothing and shaping it into how exactly I wanted it to look in future – all of the future copies that is, because whatever flaw will be on that ONE little flower, will be replicated at all the following copies. Hence being really anal about your finishing process is due!

Then they were all put together in new branches. Flowers on one branch, leaves on another, drop bezels on a third and dragons on the side.

Off to the caster again to have made rubber moulds. Why rubber? Doesn’t silver melt rubber? Yes it does and no, silver is therefore not cast into these molds. Wax is. So, out of these moulds I had 10 wax copies made, each featuring one of each flower, leaf etc.

Back to my work bench. Now I took all the branches apart and reassembled them into branches featuring identical wax flowers.

And off to the caster for the 3rd time.

One week later I had silver versions of the branches with all the identical flowers etc. Why that many identical ones? Partly because it is a way to produce several of your favorite pieces, enabling more than one to get it, partly because I will use these as part elements in jewelry. These will still be one of a kind, just with lovely, 3D flowers for instance.

So, one final renovation and then off to the caster for the 4th and last time in order to have moulds made of each of the branches and cast silver versions of them.

Here we are: several months of work has finally paid off and I feel like a dragon on its treasure. Mine! All miiiiine! Now off to play with it. Here are some of the finished pieces that have come from this batch and I am nowhere near done!

Here is the chubby version of the drop necklace with a matte surface, gildet with 18 carat gold and holding a pearl﻿

Most of the casts can be used as part elements. I have as a starter created 8 different rings with flowers.

There could be many more variations. For instance with bigger stones in the middle, cast in gold or just combined differently. This is where your imagination kicks in: What would you like? What combination and colors would make your heart go boom?

So relevant your comment re: the foredom. I learned lost wax casting while working in a dentist office. One day during lunch the Dr carved a fat 2" wax frog using the same foredom he used for fillings, and set it in plaster. After work the plaster mold had been burned out; he melted dental gold patients had given him over the past year in a crucible using a hand torch, and poured it into the burn out. Within minutes he had a solid 22kt gold frog. He added into his menagerie of gold animals. I was hooked on lost wax from that point on!